Balancing mechanism for washing machines



May 19, 1959 G. c. BAXTER 2,386,979

' BALANCING MECHANISM FOR WASHING MACHINES Filed ma 21, 1956 5Sheets-Sheet 1 A INVENTOR. Gee/'9: C fiaxfer G. C. BAXTER BALANCINGMECHANISM FOR WASHING MACHINES May 19,1959

3 Sheets-Sheet 2 Filed May 21. 1956 J N! y m m m r d m f w n 6 w 1 y 19,1959 G. c. BIAXTEVR' 2,886,979

BALANCING MECHANISM FOR WASHING MACHINES.

- Filed May 21, 1956 v 5 Sheets-Sheet 5 IN VEN TOR.

2,886,979 Patented May 19, 1959 BALANCING MECHANiSM FOR WASHING MACHINESGeorge C. Baxter, Marion, Kans., assignor to Flex-Prop Corporation,Marion, Kans.

Application May 21, 1956, Serial No. 586,137

3 Claims. (Cl. 74-573) This invention relates to new and usefulimprovements in washing machines, and has particular reference to thedynamic balancing of the rotary washing cylinder.

In washing machines particularly of the larger com mercial types whereinthe clothing or other material to be laundered is supported in ahorizontal perforated drum, said drum being rotated at a relatively slowspeed to provide a tumbling action on the material within the drum, it

has been found difficult and impractical, if not actually impossible, tospin dry the contents of the drum; that is, torotate the drum at a highspeed so that the Water in the material within the drum is drivenoutwardly by cen trifugal force through the perforations of the drum.The difficulty arises from the fact that the material being launderedcan and usually does arrange itself principally at one side of the drum,with the result that if the drum is rotated at a. speed. great enough toeffect the spin dry operation, the condition of unbalance of the drumcauses severe vibration and eccentric loading of the drum bearings, withthe resultant strain, wear, and failure of said bearings, and also apronounced tendency of the entire washing machine to be jerked or shakenloose from its moorings.

The principal object of the present invention is, therefore, theprovision in a washing machine of the class described of means wherebythe cylinder thereof is auto rnatically counterbalanced to offset anycondition of un balance caused by eccentric placement of the materialbeing laundered therein.

This object is accomplished generally by mounting the cylinder so thatit may gyrate slightly about its normal axis as a result of anyunbalanced distribution of the load therein, mounting on said cylinderan annular tank concentrically therewith, said tank being divided intose,,- mental compartments, and providingeach of said compartments withvalving means actuated by lateral displacement of the cylinder duringits gyration to selectively deliver water to or eject water from saidcompartments in such a manner as to compensate for the unbalanced loadin the cylinder.

Other objects are simplicity and economy of construction, efficiency,sensitivity, dependability and speed of operation, and adaptability foruse in a wide variety of applications.

With these objects in View, as well as other objects which will appearin the course of the specification, ref erence will be had to thedrawing, wherein:

Fig. l is a fragmentary vertical sectional view of a washing machine,being taken on line I--I of Fig. 2, showing a balancing mechanismembodying the present in vention applied thereto, with parts left inelevation,

Figs. 2 and 3 are sectional views taken respectively on lines IIII andIIIIII of Fig. 1, and

Fig. 4 is an enlarged, fragmentary sectional view taken on line IV-IV ofFig. 3.

Like reference numerals apply to similar parts throughout the severalviews, and the numeral 2 applies to a cylindrical case or housing havingits axis disposed horizontally, and having its rear end wall 4 *afiixedas by rivets 6 to a vertical standard 8 forming a portion of a rigidframe, and its forward end wall 10 being provided with a central dooropening 12 fitted with adoor closure 14. Said housing is provided at itsbottom with a drain opening 1-6 which it will be understood iscontrolled by a suitable valve, not shown.

Disposed within housing 2 is a washing cylinder 18 having a perforatedcylindrical Wall 20, a planarforward end wall 22 adjacent front housingwall 10 and havingia central aperture 24 formed therein registering withdoor opening 12, and a planar rearward end wall 26. Said cylinder isprovided internally with a plurality of vanes 28 spaced angularly aboutthe periphery thereof and ex tending radially inwardly from cylinderwall 20. Said cylinder is supported coaxially with housing 2 by means ofa hollow shaft 30. Said shaft is provided at its forward end with aflange 32 which is secured to the end wall 26 of the cylinder by meansof rivets 34. Said shaft extends rearwardly through a hole 36 providedtherefor in housing wall 4 and standard 8, and is rotatably mounted in apair of ball bearings 38 mounted in a bear ing housing lli rigidlyaffixed to said standard. The bearing 38 closest to cylinder 18 ismounted in a rubber seat 42 whereby to permit a slight movement of saidbearing laterally of the shaft for a purpose more fully described below.

A pulley 44 is fixed on a rearwardly extended portion of shaft 30, andis operably connected by means of belt 46 with an electric motor orother power unit, not shown, by means of which shaft 3'1) and cylinder18 may be rotated at various speeds. The extreme rearward end of shaft30 is carried rotatably in a bore 48 of a block 50 attached to standardit by bracket 52, and is sealed in said here by packing 54- and packinggland 56. A host:

5% or other conduit is connected to block 58 so as to furnish waterunder pressure to bore 48 and to hollow shaft 30.

A hollow annular tank 60 is disposed concentrically about washingcylinder 18 in outwardly spaced relation therefrom, being afiixedrigidly thereto by means of fasteners 62 (see Fig. 2). Said tank isdivided by radial partitions 64 into four equal segmental compartments66, 68, 7d and 72, each of which may be designated in itself as a tank.Each of said compartments or tanks has a valve 7 attached to theforwardwall thereof, said valve being supplied with water through a pipe76 communieating with hollow shaft 36 intermediate rear walls 26 and 4-of cylinder 13 and housing 2. Said pipes extend radially outwardly alongrear wall 26 of the cylinder, being secured thereto by suitable clips78, then forwardly between tank 60 and cylinder wall 20, being securedto the latter by suitable clips 80.

Each of valves 74, best shown in Fig. 4, comprises a body 82 secured totank 66 by fasteners 84 (see Fig. 3), and having a bore 86 formedtherein so as to be radial to cylinder 18, pipe 76 communicating withthe inner end of said bore. Adjacent the inner end of the bore, body 82is provided with a lateral port 88 interconnecting said bore with theinterior of the associated tank compart ment 66, 68, 76) or 72, andadjacent the outer end of the bore a port 90 interconnects the bore withthe tank compartment. Intermediate bores 88 and 90, body 82 is providedwith an air vent port 92 interconnecting bore 86 with the tankcompartment. A tube 94 secured in port 92 extends adjacent the innerwall of annular tank 60. Disposed for longitudinal movement in bore 86is a valve slide 96 which is of such length that when in its centralposition as shown in Fig. 4 it covers and closes all of ports 88, 90 and92. Said slide is provided intermediate its ends with a pair ofperipheral grooves 98 which are normally disposed respectively atopposite sides of vent port 92. Said slide has a yoke 100 securedtherein and extending forwardly therefrom through a slot 102 formed invalve body 82 longitudinally of bore 86. Said yoke carries a pair ofrollers 104 and 106. Said rollers are disposed on axes parallel to theaxis of cylinder 18, and have rolling contact respectively with theouter and inner surfaces of a cylindrical flange or track 108 which isrigidly secured to the inner surface of front wall of housing 2, inconcentric relation with shaft 30.

In the washing and rinsing portions of the operating cycle, the cylinder18 is turned at a relatively slow speed, the material therein beingelevated and dropped by vanes 28 in a tumbling action in the washing orrinsing solutions contained in housing 2 and entering cylinder 18through the perforations thereof. The means for introducing the variouswashing and rinsing solutions into the housing, and for controllingdrain 16 to retain or eject said solutions are not here shown. They arenot involved in the present nvention, except that it will be noted thatannular tank 60 is spaced sufiiciently far away from cylinder 18 so asnot to interfere with the circulation of solutions through theperforations of the cylinder.

When it is desired to spin dry the material being washed, drain 16 isopened and the rotational speed of cylinder 18 is greatly increased.Then, if a greater portion of the material being laundered is disposedat one side or the other of the cylinder, and is held against thecylinder by centrifugal force, the cylinder will be unbalanced therebyand there will be a strong tendency for the cylinder to gyrate about itsnormal axis, the direction of the ofiset of the geometric axis of thecylinder from its normal rotational axis being at all times toward theheavy side of the cylinder, and the degree of offset being proportionalto the mass of the unbalancing weight of the material Within thecylinder. This gyration would occur to some extent by flexing of shaft30, even if bearings 38 were fixed. However, to permit said gyration tooccur without objectionable overloading of said bearings, and toincrease the sensitivity of the device, one of said bearings is renderedtransversely yieldable by its retention in resilient rubber seat 42, aspreviously described.

Assuming that the unbalancing load in cylinder 18 is centered at theside thereof subtending tank compartment 66, the cylinder gyration willforce compartment 66 away from the axis of shaft 30, and the oppositecompartment 70 toward said axis. Considering first the valve 74 servingtank compartment 66, it will be seen that slide 96 thereof will be heldradially stationary by the engagement of its rollers 104 and 106 withtrack 108, and valve body 82 will be forced outwardly over said slide.This opens port 90, and water in tank compartment 66 flows outwardly bycentrifugal force through port 90 and bore 86 into housing 2. At thesame time, valve 74 serving the opposite tank compartment 70 is affectedin a reverse manner, body 82 being forced inwardly over slide 96. Thisopens port 88, and water under pressure from the associated pipe 76flows through valve bore 86 and port 88 into compartment 70. Theseoperations continue, water being drained from compartment 66 and addedto compartment 70, until the overall mass carried by shaft 30 isbalanced dynamically around said shaft, and the gyration about the shaftaxis ceases. As the gyration gradually subsides, valves 74 graduallyreturn to their neutral positions, closing ports 88 and 90 thereof. Thecylinder may then be safely rotated at a speed suificient to drive waterfrom the contents thereby by centrifugal force until said contents arein the usual damp dry condition.

It will be seen that this action is automatic and continuous, and thatthe degree of gyration of the cylinder need only be very slight at themost, the correction taking place almost as rapidly as the gyration candevelop. The speed of response of the device is of course determined bythe speed with which water can be added to or drained from the tankcompartments, and is determined by the capacity of valves 74. Thisresponse speed should be sufiiciently great to correct any condition ofbalance during the time the cylinder is gradually accelerated to fullspeed. It will be seen also that the speed of response of the device isenhanced by the double action thereof, that is, the simultaneousaddition of water to one compartment and removal of water from theopposite compartment. This substantially cuts in half the amount ofwater which otherwise would have to pass through any one of the valvesif the device functioned solely either by the addition or by thesubtraction of water. This double action also renders it unnecessary tohave any particular amount of water in the tank compartments at thestart of operation. Normally the tanks will be partially filled, and thedouble action will occur as described. However, if the compartmentsshould happen to be full, then the device can function solely bydraining water from the tank compartment at the heavy side of thecylinder, and if the compartments should be empty, the device canfunction solely by adding water to the compartment at the light side ofthe cylinder.

Sensitivity of the device is provided by placing the rollers 194106which control valves 74 at the extreme forward end of cylinder 18, inwhich position they are subjected to the greatest degree of offset ofthe cylinder due to gyration thereof. The sensitivity as well as speedof response could also be increased by using more than the four tankcompartments shown. Three or any larger number of compartments could beused.

It will be seen in Fig. 4 that whenever valve slide 96 is moved to openeither of ports 88 or 90, one of grooves 98 will register with vent port92, so that the associated tank will be vented to housing 2 through saidgroove and slot 102. This venting is of course necessary to permit easyand rapid ingress and egress of water to and from the tank. Tube 94extends to the radially inward portion of the tank since the water inthe tank is forced to the outer portion of the tank by centrifugal forceduring operation. It would be possible to use permanently open vents,for example in the inner cylindrical walls of the tanks. However, inthat case, or with any open vents, certain of the tanks would drainwhile others would not when the machine comes to rest, and therefore themachine would necessarily start under a condition of extreme unbalancewhen next operated. It is therefore desirable that the vents closeautomatically as shown except when water is being added to or removedfrom the tanks.

While I have shown and described a specific embodiment of my invention,it will be apparent that many minor changes of structure and operationcould be made without departing from the spirit of the invention asdefined by the scope of the appended claims.

What I claim as new and desire :to protect by Letters Patent is:

1. In a washing machine, a housing, a cylinder carried rotatably in saidhousing and adapted to carry the material to be washed, and to gyrateslightly about its normal axis during rotation if said material isdistributed in an unbalanced relation about the axis thereof, aplurality of tanks aflixed to said cylinder in spaced relation from theaxis thereof and in angularly spaced relation around said axis, meansconnecting each of said tanks to a source of liquid under pressure, asupply valve associated with and mounted on each of said tanks andcontrolling the passage of liquid through said connecting means, each ofsaid valves having an operating member, and a circular track memberaflixed in said housing in concentric relation with the normal axis ofsaid cylinder, said valve operating member engaging said track member atall times and being operable by movement of said cylinder transverselyto its axis whereby when said cylinder moves transversely to its normalaXiS. uring unbalanced gyration, one or more of said valves will beopened to deliver liquid to the tank or tanks at the light side of saidcylinder.

2. The structure as recited in claim 1 wherein each of said tanks isprovided also with a drain port and a valve controlling said drain port,said supply and drain valves comprising a single compound valve operableby said valve operating member, said operating member functioning toclose both of said valves when said cylinder rotates on its normal axis,to open said drain valve when that portion of the cylinder adjacentwhich said compound valve is mounted moves away from the normal axis ofthe cylinder during gyration thereof, and to open said supply valve whenthat portion of the cylinder adjacent which said compound valve ismounted moves toward the normal axis of the cylinder during 15 gyrationthereof.

3. The structure as recited in claim 2 wherein said compound valvecomprises a body member mounted on the tank associated therewith andhaving a bore formed therein radially to said cylinder, liquid underpressure being supplied to the inner end of said bore and the inner andouter ends of said bore and interconnecting said bore with theassociated tank, and a slide carried for longitudinal movement in saidbore and having a length sufficient to close both of said ports, saidvalve operating member being fixed to said slide and engaging said trackwhereby said slide is held radially stationary during balanced rotationof said cylinder, and whereby during unbalanced gyration of saidcylinder, said valve body will be moved radially inwardly or outwardlyalong said slide to open one or the other of said ports selectively.

References Cited in the file of this patent UNITED STATES PATENTS305,026 Stillman Sept. 9, 1884 1,604,748 Grauer Oct. 26, 1926 2,224,241Verdier et a1. ]Dec. 10, 1940 2,584,942 Thearle Feb. 5, 1952 202,687,215 Armstrong Aug. 24, 1954 outer end of said bore being open,said body having a pair of ports formed therein respectively adjacentthe FOREIGN PATENTS 136,390 Germany July 8, 1952

